Method of making shoe sole



. April 21, 1970 E. R. ouuQlEi' 3,506,994

METHOD OF MAKING SHOE SOLE Original Filed June 5, 1967 United States Patent ()7 3,506,994 METHOD OF MAKING SHOE SOLE Emil R. Ouimet, 31 Country Club Drive, Brockton, Mass. 02401 Original application June 5, 1967, Ser. No. 643,501. Divided and this application Mar. 26, 1969, Ser. No. 811,690

Int. Cl. A43d /00 U.S. Cl. 12-146 6 Claims ABSTRACT OF THE DISCLOSURE A method of making a sole element for shoes having an edge band of thermoplastic material in lieu of a textile or other tape.

This is a division of application Ser. No. 643,501, filed June 5, 1967.

BACKGROUND OF THE INVENTION Several types of footwear, for example, slippers, hereinafter referred to simply as shoes, comprise, as a sole element, such as may be referred to in accordance with the particular type of shoe, as a midsole, a slip sole and an insole or the like, which is or may be, to a certain extent, visible in the finished shoe and which, because of its visibility, or because the sole blank needs reinforcement, is customarily provided with a marginal band which may be confined to its forepart or to its rear portion or which may extend about the entire peripheral edge, and which customarily has been provided by folding a textile or other tape about the edge of a sole blank and permanently securing the tape to the sole blank by sewing or by adhesive.

Although as to certain soles this band contributes little, if anything, to the functional value of the shoe, the provision of a textile tape and the assembling and the attaching of the tape to the sole blank adds an appreciable amount to the cost of manufacture.

SUMMARY Briefly stated, the present invention contemplates the application of a synthetic plastic material in liquid condition to a selected portion or to the entire peripheral edge of a sole blank to form a coating for the edge face and for a predetermined width of the margin, inwardly from the edge, at both upper and lower faces of the sole blank. After the plastic has been applied, the blank, with its marginal coat of plastic, is exposed to conditions such as to cure the plastic. For example, if the plastic be of thermosetting tape the blank with its marginal coat of plastic is placed in a curing chamber where it is subjected to a temperature of, for example, 350 F. for a period such as completely to cure the plastic.

The operation of applying the fluid to the edge of the sole may be carried out in any appropriate way, for example, by the use of a suitably devised implement which is manually employed in drawing a stripe of the liquid coating along the sole edge, although it may be applied by means of a mechanical device having means for gripping and turning the blank while moving that portion of the edge of the blank, which is to be coated, through a body of the liquid material after which the blank, with the plastic still in fluid condition, may be placed upon a suitable rack or other support and installed in a heating chamher.

A sole resultant from the practice of the present invention, and apparatus useful in the manufacture of said insole, are illustrated more or less diagrammatically in the accompanying drawings wherein:

3,506,994 Patented Apr. 21, 1970 FIG. 1 is a plan view of a sole embodying the present invention drawn to smaller than actual size;

FIG. 2 is a fragmentary section, to much larger size, on the line 22 of FIG. 1;

FIG. 3 is a view similar to FIG. 2, but showing an edge finish of somewhat dilferent transverse shape;

FIG. 4 is a fragmentary elevation illustrative of apparatus such as might be used in the practice of the invention, but for clarity in illustration omitting the plastic material; and

FIG. 5 is a diagrammatic vertical section illustrating apparatus such as may be suitable for curing the plastic after its application to the sole blank.

Referring to the drawings, the numeral 10 (FIGS. 1, 2, 3 and 4), designates a sole blank of conventional type and material, usually prepared by a die-cutting process from sheet material and having an outer edge face 11 which, when the sole is in use, is substantially vertical the opposite, normally horizontal faces 13 and 14 usually being parallel and perpendicular to the edge face 11. In accordance with the present invention the edge face 11 and marginal portions of the faces 12 and 13 are concealed by a band F consisting of or comprising, in major portion, a unitary body of a synthetic plastic material which is integrally bonded to the blank 10' by its inherent adhesiveness. This finish band F, as illustrated, for example, in FIG. 2, is generally U-shape in transverse section, comprising the U-bend 15a which unites substantially parallel leg portions 151) and 150 respectivelythe bend 15a concealing and adhering to the edge face 11 of the sole blank and the leg portions 15b and 150 of the U-shaped band overlying and adhering to the margins of the top and bottom faces 12 and 13, respectively, of the blank. As shown in FIG. 2 the thickness of the bend 15a is substantially the same as the thickness of the leg portions 15b and 150 of the band, The Width of the respective leg portions 15b and 15c inwardly from the edge 11 of the blank may be as great or as little as may be desired for any given type of sole, for instance /a inch.

In the arrangement illustrated in FIG. 3, the finish band F is shown in transverse section as being somewhat thicker at the bend portion of the U than at the leg portions, for example, being approximately 0.5 mm. thick, with the result of providing a bead-like finish band whose exposed outer surface, in transverse section, is arcuate, providing a desirable ornamental effect.

The material which forms the finish band in either case is applied to the edge portion of the blank while in a liquid or semi-liquid condition and may be applied, for example, as a purely manual operation by the use of a suitably designed implement (not here shown) containing a supply of the liquid material and having a delivery orifice or nozzle such that by drawing the orifice or nozzle along the marginal portion of the blank, a band of the desired shape and dimensions will be deposited. Preferably the material employed in forming the head is a quick-setting plastisol which is applied in liquid form and at a viscosity such that it will adhere to the edge of the sole without dripping off in the short interval between its application to the sole blank and its response to a curing temperature. One such material, among others, is that sold by Chemical Products Corporation of Providence, R.I., under the name of Chem-O-Sol. This is a vinyl chloride dispersion, devoid of volatiles, which sets within a period of three minutes when exposed to a curing temperature of 350 F. and which, when cured, may have a Shore D hardness; which is available at the desired viscosity for this particular purpose, and in assorted colors, and which is impervious, after curing, to most detergents, perspiration, or oil. This material is stable in liquid form until subjected to the curing temperature and becomes solid with substantially no change in volume or weight.

While such a thermosetting plastisol is considered preferable in making the edge band for a sole blank, it is contemplated that instead of using such a normally liquid thermosetting plastisol, a hot-melt vinyl dispersement might be employed which would be applied hot and flowable, but which would cool substantially instantly, when exposed to the ambient temperature, after application to provide a finish having the desired characteristics.

Obviously, if desired, any suitable material, for example, a granular substance, or very short fibers might be incorporated in the liquid plastisol to impart special characteristics, either for physical or ornamental purposes.

While as above noted, the plastisol may be applied by a pure manual operation, using for the purpose an appro priate implement, it is preferred to use some suitable mechanism whereby the marginal portion of the sole may be automatically advanced with reference to a body of plastic so as to pick up the plastic progressively at that portion of the margin of the sole blank which is to be provided with the finish band. Thus, for example, as diagrammatically illustrated in FIG. 4, an applicator (of a known type) in the form of a rotary, peripherally grooved roll R may constitute the holder for the fluid material, this roll being mounted on a rotatable shaft S and having the peripheral groove G which is of a transverse sectional shape approximating that of the shape of the desired edge band which is to be applied. The roll R is shown with its lower portion dipping into an open-topped container 16 (shown as having coils 17 by means of which it may be heated or cooled), and having a supply conduit 18 through which liquid plastic may be supplied to the container 16 from any suitable source (not shown) and at a controlled rate such as to keep the level of the liquid plastic P substantially constant within the container.

For ease in illustration, the peripheral groove G in the roll R is of somewhat greater dimensions than might be required-it being understood that the transverse shape of the groove will be proper to form a band such, for example, as shown in either of FIGS. 2 or 3, respec tively, of the desired dimensions.

As shown in FIG. 4 the sole blank is shown as interposed between rotating clamping discs 23 and 24 carried by shafts 21 and 22 respectively, whose axes are inclined to each other so that the sole contacting faces of the discs 23 and 24 converge toward each other at a steep angle. The discs 23 and 24 would be resiliently urged toward each other by any suitable means, for example, by mounting the shafts 21 and 22 in bearings in which the shafts may move axially with suitable springs (not shown) urging them toward each other, and with means for driving these shafts at the same angular velocity. With this arrangement when a sole blank is interposed between the discs 23 and 24 and the latter are rotated, the blank will be gripped and turned thereby slowly revolving the sole blank about a varying axis whereby the edge portion of the blank will always remain at the same depth within the groove of the roll R, and the margin of the blank will thus pick up adhesive plastic from the roll R, forming an ed ge finishing band according to the contour of the groove in the roll. Apparatus of the general type of that shown in FIG. 4 is well known for other uses.

It will be understood that the blank will be inserted manually between the discs 23 and 24 and will remain between the discs while such portion of the periphery of the blank as may be desired is traversed through the groove in the roll R. If, as shown in FIG. 1, the finish band is to extend along the entire edge of the sole blank, then the sole would make one complete revolution while undergoing the treatment. On the other hand, if only a portion of the sole is to be treated, then the blank will be inserted between the discs in such a way that during a partial revolution of the blank the band will be applied to the desired portion, only, of the sole blank and the blank thus removed from between the parts 23 and 24. Simple experiments will inform the operator as to how to obtain the desired result.

After the fluid has been applied to the sole blank, the blank, with its band of sticky material, will now be exposed to such treatment as may be necessary to cause the plastic material to become hard and permanent. Such treatment, as above suggested, may include the exposure of the blank to an elevate-d temperature and for a length of time appropriate to cure the particular materialor if the material be of the thermosetting type, mere exposure of the blank with its marginal band to ambient temperature or to a refrigerating temperature will cause the plastic to set.

Thus, as diagrammatically suggested in FIG. 5, the character H designates the wall of a suitable housing provided with conditioning coils C or the like whereby the interior temperature may be kept substantially uniform and such as to cure the particular plastisol as the soles S are advanced through the chamber while resting upon the upper run of an endless conveyor K trained about pulleys P and driven at a predetermined speed, for example, by a motor M.

While one desirable embodiment of the invention has herein been disclosed by way of example, it is to be understood that the invention is broadly inclusive of any and all modifications.

I claim:

1. Method of making a shoe sole comprising providing a polyvinyl plastisol in liquid condition, providing a sole blank, so relatively moving the sole blank, while its peripheral edge is immersed to a predetermined depth in a body of the liquid as to coat the edge face and marginal portions of the upper and lower surfaces with the liquid, and exposing the blank with its edge coating of plastisol to conditions such that the plastisol becomes permanently hard and shape-retaining.

2. Method according to claim 1, wherein the plastisol is of thermosetting type and, after the band of liquid plastisol has been applied to the marginal portion of the sole blank, the blank is conveyed through a curing chamber within which the temperature is maintained at approximately 350" F., while band is advanced at a rate such it is subjected to said temperature for a period of the order of three minutes.

3. Method according to claim 1, wherein the plastisol is of thermoplastic type, heating the plastisol to liquefy it before applying it to the sole blank and after applying it to the blank, subjecting the blank to a temperature such that the plastisol sets and becomes permanently hard and shape-retaining.

4. The method of providing a shoe sole blank with a marginal band of approximately U-shape in transverse section and with the legs of the U disposed at opposite faces, respectively, of the blank, and wherein the edge face of the blank is within the bend of the U, said method comprising providing a holder having a cavity of generally U-shape in transverse section and of a minimum width between its legs at least as great as the thickness of the blank, supplying coating material in liquid form to said cavity, so introducing the peripheral edge of the blank into the cavity that the midplane of the blank is substantially vertical and equally spaced from the opposite walls of the recess, and so moving the blank relatively to the holder as progressively to coat the edge face, at least, of the blank with the coating material until a finish band of desired width coats the edge face of the blank and marginal portions of the top and bottom faces of the blank, and thereafter exposing the blank to a treatment such as to cause the coating to set and become permanently hard.

5. A method according to claim 4, further characterized in that the holder is a rotary roll and the cavity is a peripheral U-shaped groove, providing a body of adhesive within which the lower portion of the roll is immersed, slowly rotating the roll and turning the blank about a varying axis parallel to that of the roll so that that portion of the periphery of the blank which is to be 6 coated with adhesive is progressively advanced relatively exposing the blank with its marginal coat of plastic to conto the roll while within the peripheral groove. ditions such as to cause the plastic to set and become 6. Method of providing a sole element for a shoe with permanently hard and shape-retaining. an edge bead of a synthetic plastic in lieu of a textile 0r References Cited other tape, which comprises as steps: providing a sole 5 blank, applying a synthetic plastic material in liquid con- UNITED STATES PATENTS dition to the peripheral edge of said blank to form a coat- 2 4 ing on the edge face and for a predetermined width of the ggzg zg g g margin, inwardly from the edge, at both upper and lower faces of the blank and, after the plastic has been applied, 10 PATRICK D. LAWSON, Primary Examiner 

